In 2013, photographer and documentarian Arthur Drooker was researching a project on historical re-enactors when he came across a subculture that, despite being a history buff, he hadn't realized existed. "I stumbled across the Association of Lincoln Presenters and it just so happened they were about to have their annual convention," Drooker tells me. "I said no contest, that’s what I’m doing now. I put the other idea on the back burner."

That was the first official convention Drooker had ever attended, and it seemed he had a knack for it. Tall and thin, Drooker fit in with the hundreds of Lincoln impersonators attending the convention in Columbus, Ohio—many of whom commented that he would make a great young Lincoln (at the time, he was actually four years older than Lincoln was when he died). The Lincoln convention, as it would turn out, was just the first of a long list of conventions he would attend and document over the next few years. His new book, Conventional Wisdom, collects 94 photographs that chronicle his experiences at gatherings like Merfest, Fetishcon, the World Clown Association convention and more.

After his experience with the Association of Lincoln Presenters, Drooker began taking suggestions from friends and researching conventions online, traveling to the conventions that looked most interesting to him. "When you start looking into a project, at a certain point it starts talking back about what it is and what it needs, what should or shouldn’t be in it," says Drooker. What emerged was a focus on the smaller or quirkier conventions that often fly under the radar. Drooker started getting picky: "No Comic-Con or Elvis Presley or Star Trek," he says. "They're so well-attended and well-known that even if you haven’t been to one you feel like you have because of the familiarity of the subject in popular culture."

The 10 Drooker ended up attending—some more than once—vary wildly from bronies (aka super-fans of My Little Pony) to military historians to furries. At the convention for the latter, called Anthrocon, Drooker met a woman dressed up in a rabbit costume ("a wild looking bunny that puts Jessica Rabbit to shame"), who Drooker had noticed around the convention but had been nervous to approach. Noticing him from across the room, she pointed at him and beckoned him over to take her picture, then told him about some aspects of the furry culture that rarely get attention. "She was easily one of the smartest people l have ever met," says Drooker. " She told me about the concept of fursona," a persona, or alter ego, of a person in the furry community, which conveys either their innermost personality or who they aspire to be. "It involves some deep psychology that’s way more interesting than some deviant sexual practice. I wanted to capture something more important, the deeper thing that’s going on there."

Despite each conference's esoteric traditions and eccentricities, Drooker says the more he attended, the more he recognized a commonality in all of them. "When I met and interviewed people at these conventions someone without fail would tell me 'it's like a family reunion,'" he says. "For a lot of these folks, it's the highlight of the year. And even I could feel the buzz—it's hard not to get swept up in it yourself."

For more of Drooker's convention photos, check out the slide show above. To find out more about Conventional Wisdom the book, go here.